cmattox,

Since it seems you will be enjoying Dublin City it probably makes most sense to stay in the city center and depart for the airport on Sunday morning.

Take a look at:

Bewley's Ballsbridge (short DART ride to city center)
Schoolhouse Hotel
Jury's Inn Christchurch

Many others have lower rates for a two-night or more stay. Suggest you look at various hotels and do a price comparison. Many are offering specials now.

Michele